page_title: USAir Flight 405
section_title: Developments in deicing
hierarchical_section_title: USAir Flight 405 / Aftermath / Developments in deicing
context_page_description: USAir Flight 405 was a regularly scheduled domestic passenger flight between LaGuardia Airport in Queens, New York City, New York, and Cleveland, Ohio. On March 22, 1992, a USAir Fokker F28, registration N485US, flying the route, crashed in poor weather in a partially inverted position in Flushing Bay, shortly after liftoff from LaGuardia. The undercarriage lifted off from the runway; however, the airplane failed to gain lift, flying only several meters above the ground. The aircraft then veered off the runway and hit multiple obstructions before coming to rest in Flushing Bay, just beyond the end of the runway. Of the 51 people on board, 27 were killed, including the captain and a member of the cabin crew.
  A similar accident had happened three years before in 1989, when Air Ontario Flight 1363 crashed shortly after takeoff at Dryden Regional Airport after ice had accumulated on the wings and airframe. Out of 69 passengers and crew, 24 were killed.
  The subsequent investigation revealed that due to pilot error, inadequate de-icing procedures at LaGuardia, and several lengthy delays, a large amount of ice had accumulated on the wings and airframe.
context_section_description: In the years that followed the accident, airlines started using Type IV deicing fluid, which is more effective than both Type I and Type II fluids. Type IV fluids stick to aircraft for up to two hours. Chicago O'Hare International Airport was the first to introduce deicing facilities at the runway, something which has now become commonplace.
  Aircraft themselves now have more sophisticated deicing systems that can be used on the ground and in the air. Many modern civil fixed wing transport aircraft, for example the Boeing 737, use anti-ice systems on the leading edge of wings, engine inlets and air data probes using warm air. This is bled from engines and is ducted into a cavity beneath the surface to be anti-iced. The warm air heats the surface up to a few degrees above freezing, preventing ice from forming. The system may operate autonomously, switching on and off as the aircraft enters and leaves icing conditions.
  Ground deicing technologies are also developing, and a newer technology is infrared deicing. This is the transmission of energy by means of electromagnetic waves or rays. Infrared is invisible and travels in straight lines from the heat source to surfaces and objects without significantly heating the space (air) it passes through. When infrared waves strike an object, they release their energy as heat. This heat is either absorbed or reflected by the cooler surface. Infrared energy is continually exchanged between "hot" and "cold" surfaces until all surfaces have reached the same temperature (equilibrium). The colder the surfaces, the more effective the infrared transfer from the emitter. This heat transfer mechanism is substantially faster than conventional heat transfer modes used by conventional deicing (convection and conduction) due to the cooling effect of the air on the deicing fluid spray.
  Aircraft deicing vehicles have also improved since the accident, usually consisting of a large tanker truck, containing the concentrated de-icing fluid, with a water feed to dilute the fluid according to the ambient temperature. The vehicle also normally has a cherry picker crane, allowing the operator to spray the entire aircraft in as little time as possible; an entire Boeing 737 can be treated in under 10 minutes by a single de-icing vehicle. Airport runways are also deiced by sprayers fitted with long spraying arms. These arms are wide enough to cross the entire runway, and allow de-icing of the entire airstrip to take place in a single pass, reducing the length of time that the runway is unavailable.
caption: An American Airlines MD-80 aircraft being deiced at Syracuse Hancock International Airport
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